In the case of the redundant communication network according to WO 2005/053221, a fault on a main cable section is isolated by the branch elements provided there. Switches in the main cable separate off the faulty cable. By redundancy switching provided using a redundancy manager, the branch elements sited closest to the location of the fault are supplied with operating voltage from the side facing away from the fault. The redundancy manager uses the branch elements to check the faulty main cable section from both sides by applying a test current and evaluating the current and voltage. With a test of the main cable section from both sides by the same principle the no-fault case is not recognized. In order to cancel out a separation of the main cable in the case of a known fault situation, after carrying out a repair the procedure until now has been manual reactivation e.g. using a key button and a switching pulse triggered by said button.
It is disadvantageous in the respect that a user intervention is always necessary.